Cylindrical surface lapping machine



April 30, 1946. A. M. DRAKE 2,399,477

CYLINDRICAL SURFACE .LAPPING MACHINE Filed May 28, 1945 4 Sheets-Sheet l [Will/70R Alt/912M fira/ie April 30, N460 A. M. DRAKE 2,399,477

I CYLINDRICAL SURFACE LAPPING MACHINE Filed May 28, 1945 4 Sheets-Sheet '2 Fly .2

Ill M25701? Alden/12f fira/i'e A. M. DRAKE 2,399,477

CYLINDRICAL SURFACE LAPPING MACHINE 4 Sheets-Sheet 4 Filed May 28, 1945 W KW AYI'OR/VEY Patented Apr. 30, 1946 CYLINDRICAL SURFACE LAPPING MACHINE .Alden M. Drake, West Hartford, Conn, assignor to Niles-Bement Pond Company, West Hartford, Conn, a corporation of New Jersey Application May 28, 1945, Serial No. 596,179

Claims.

This invention relates to lapping machines and particularly to a lapping machine for finishing cylindrical surfaces, either external or internal, to extremely close limits of dimensions, roundness, uniformity of diameter and smoothness.

A primary object of the invention is to provide actuating mechanism for the tool and work including rotating means for the work piece bein lapped, or for the lapping tool, and also mechanism to actuate one of these members longitudinally and also simultaneously oscillate this member about the axis of rotation of the work or tool, these movements taking place while the traversed and oscillated memberis free to adjust itself upon the surface of the rotating member.

Another object of. the'invention is to provide an improved holder and supporting means for the tool or work being lapped, whichever memher is traversed and oscillated, so that this member may be actuated longitudinally and also oscillated while being supported freely and uniformly upon the rotating member for adjustment upon the surface of the rotating member.

Another object of the invention is to provide resilient means to aid in efiecting the actuating movements of the member being oscillated during its traversing movements and also'to support the member being oscillated for free adjustment upon the rotating member in any direction other than those in which it is actuated.

With the above and other objects in view the invention consists in the features of construction and operation set forth in the following specification and illustrated in the accompanying drawmgs.

In the accompanying drawings annexed hereto and forming a part of this specification, I have shown the invention embodied in a lapping machine for plain internal cylindrical surfaces but it will be understood that the invention can be otherwise embodied and that the drawings are not to be construed as-defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawings: 7

Figure 1 is a side elevation, partly in section, showing the. rotating, oscillating and traversin mechanisms of the machine, the traversing mechanism being shown in its extreme forward position to more clearly show the oscillating mechn ma 'Fig-.' 2 is a front elevation showing a work piece mounted in position on the lapping tool.

Fig. 3 is a sectional view taken on the plane of line 33 of Fig. 1.

Fig. 4 is a detached view showing the front elevation of a work piece supporting member.

Fig. 5 is a plan View in section of this supporting member, and

Fig. 6 is a diagram of the hydraulic operating mechanism.

In the above mentioned drawings there has been shown but one embodiment of the invention which is now deemed preferable, but it is to be understood that changes and modifications may be made within the scopeof the appended claims without departing from the spirit of the invention.

In the annexed drawings the figures show a machine designed particularly for internal cylindrical gages of relatively small diameter. These gages are usually adjustable for slight variations in diameter by being radially slotted at angularly spaced portions partially through their walls. They are adjusted to predetermined sizes and retained in adjusted condition by any usual means. The present application represents an improve ment upon and development from the construc tion shown in my Patent No. 2,379,693, granted July 3, 1945.

Briefly, and in its preferred aspect, the invention may include the followin principal parts: first, a base member having a spindle rotatably mounted on a horizontal axis and preferably alternately rotated in opposite directions by a reversing hydraulic motor; second, an oscillating member adapted to oscillate about the axis of rotation of the spindle; third, traversing mechanism for the work piece being lapped, this mechanism being moved in a direction parallel to the axis of rotation of the spindle to traverse the work piece along the lapping member; fourth, a supporting member for the holder within which the work piece is mounted, the supporting memher being carried by a projection on the traversing mechanism serving to support the work piece in position for lapping and adapted for free ad-- justment about an axis normal to the axis of rotation of the spindle.

Referring more in detail to the figures of the drawings, and first to Fig. 1, there is shown supported within a suitable base ill a rotatable spindle l2 which may be rotated by any preferred means, such as by the hydraulic motor [4 attached by means of a flexible coup-ling l6 located at the rear end of the spindle I2. The spindle l2 may, as shown, be rotatably supported within suitable anti-friction bearings l8 housed within anoscillating member 20 which presently will be described more in detail. At the forward end. of the rotatable spindle I2 is provided a suitable chuck 22 enabling an arbor 24 to be detachably supported co-axially therein. This arbor 24 may comprise a usual form of lapping tool, as shown in the accompanying drawings, or may be the cylindrical surface being lapped in other embodiments of the invention.

The oscillating member referred to above and within which the spindle I2 is supported is, as shown in Fig. 1, mounted for oscillation upon suitable anti-friction bearings 26 and is provided with a segmental gear member 28 near its rear end. This gear segment has teeth meshing with rack teeth formed on the intermediate portion of a double ended piston operating within opposed cylinders 32 disposed transversely of the base Ill and oscillating member 20 so that reciprocatory movements of the piston 38 within its cylinders 32 will oscillate this segmental gear 28 and member 20. As shown in Fig. 3, the cylinder 32 may have heads 34 on eitherside of the base and the piston 30 may be operated therein by any suitable means, such as by admitting fluid under pressure alternately to the opposite ends of the cylinders 32 adjacent the heads 34 by means indicated in the diagram Fig. 6.

On the forward end of this oscillating member 20 is an upwardly extending arm carrying a horizontal forwardly extending member 36 having resiliently suspended horizontal parallel bars 38 adapted during the lapping operation to engage opposite sides of a supporting member for the work piece W mounted on the rotating arbor 24.

To resiliently support the bars 38 they may be attached to the member 36 by means of suitable coiled wire springs similar in operation to those made use of in the above mentioned application.

Also formed on the segment gear 28 are adjustable tappets 29 adapted to strike and oscillate a valve operating member 3| controlling admission and exhausting of fluid to the opposite ends of cylinder 32 to reverse its movement. By angular adjustment of the tappets 29 on the segment member 28 the arc of oscillation of the member 20 and its forwardly extending member 36 may be varied.

In order to effect longitudinally traversing of the work piece W being lapped along the arbor 24, a bracket 40 having an elongated sleeve 42 extending rearwardly and horizontally therefrom is mounted within the upper part of the base It]. A piston 44 is provided operating within this sleeve and supported by a hollow rod 46 held in fixed position at one end relative to the base l0. By applying fluid under pressure to within this sleeve member on either side of the piston 44, as by means of the hollow rod 45 or sleeve 5| extending within the sleeve 42, the bracket 40 may be reciprocated in a direction parallel to the spindle l2 and arbor 24. To control the length of the reciprocatory movements of the bracket 40 and its actuating sleeve 42 a valve actuating rod 43 having adjustable collars 45 thereon may be mounted for engagement by a projecting portion 41 of the bracket. The operation of this valve rod 43 will be obvious by an inspection of the diagram Fig. 6.

As shown in Fig. 1 the fiuid supply means for traversing the bracket 40 and its sleeve are at one end of the base within a member 49. Supply and exhaust ports are provided therein admitting and drawing fluid from within the sleeve 42 on opposite sides of the piston 44. The hollow rod 46 admits fluid to the forward end of the cylinder or sleeve 42 within which piston 44 operates and a sleeve 5| admits fluid from other ports to the rear side of piston 44. As the hydraulic mechanism for reciprocating the bracket 40 forms no part of the present invention, it is not thought that further description of their construction is necessary.

Supported within the bracket 40 or arm of the reciprocating member is a supporting or actuating member 52 for the work holder 64. This member 52 has a cylindrical portion 54 entering a horizontal transverse opening within the bracket 40 permitting the supporting member 52 to oscillate about a horizontal axis disposed at right angles to the axis of the spindle l2.

The supporting member 52, as shown in Figs. 4 and 5, comprises a two-part yoke member spring pressed together. One side of the yoke forms an integral part of the member 52 and the opposite yoke member 56 is attached thereto for movement directly toward and from the integral yoke member. Within a reces 58 formed in the member 52 fits a projection 60 forming a part of the yoke member 56. A spring 62 within the projection 60 bearing against the end face of the projection at one end and against an abutment threaded to a bolt extending through the integral yoke member resiliently forces the yoke members toward each other. Between the adjacent faces of the yoke members extend arms 66 formed on the work holder 64. The arms of the yoke portions of the members 52 and 56 are extended sufliciently to permit oscillation of the work holder 64 through relatively wide arcs.

In operation of the machine selected to illustrate the invention the work piece W, an internal gage, is clamped within a holder 64 having diametrically opposite arms 66 extending therefrom which pass between the two springpressed yoke members 52 and 56 so that the holder 84 may be oscillated about its axis on the arbor 24. The upper arm 66 of the holder 64 engages within the resiliently supported bars 38 on the oscillating member 29 so that the Work holder 64 while supported between the yoke members will be oscillated. The arbor ;24 and spindle l2 are rotated in one direction and reversed alternately after predetermined numbers of revolutions by the motor l4. For this purpose any means may be employed to control the rotation of motor l4. Preferably a valve rod 68 similar to rod 43 for controlling the length of traverse movements of the bracket 40 may be used disposed on the opposite side of the base from rod 43. On this rod 68 are adjustable discs 10 operating to throw the control valve for motor l4. The movements of the bracket 40 therefore reverse direction of rotation of the spindle I2 and arbor 24.

Simultaneously with the traversing movements of the bracket 48 the oscillating member 20 is actuated to oscillate the holder 64 and work piece W by its engagement with the resiliently mounted bars 38. The bracket 48 or arm on the reciprocating member is reciprocated parallel to the direction of the spindle l2 and arbor 24 to traverse the work piece W being lapped along the lapping tool, these movements by means of collars ID on valve rod 68 control reversal of rotation of the spindle l2.

During this operation it will be seen that the work holder 64 may oscillate about the axis of the cylindrical end 54 of the yoke supporting member 52 and at all times the work holder 64 and work piece W being lapped are yieldingly supported for free adjustment upon the arbor 24. To disengage the work piece W from the arbor 24 it is only necessary to swing the arm 40 out of engagement with the work holder 64 about the axis of its sleeve 42 and manually remove the holder 64 from the forward end of the arbor 24.

Referring briefly to the hydraulic diagram, a pump Hi directly connected to its driving motor 72 supplies fluid under pressure to a distribution system at controlled pressures determined by relief valves 14 and It. In addition to relief valves 14 and 1B supplemental relief valves 15 and 11 may be provided. Valves 14 and 15 may be permanently set for normal operating pressure and valves 15 and 1! conveniently positioned for adjustment from time to time during operation of the machine. By means of valve 15 the pressure applied to rotate the spindle l2 and arbor 24 can be conveniently changed and by valve 11 the pressure applied to operate the traversing mechanism 40 and 42 and oscillating member 20 may be controlled.

The spindle rotation motor [4 is of the rotary hydraulic type and is controlled by distributing valve 18, the speed of which can be controlled by a throttle valve 80. Reversals of this motor 14 are controlled by axial movement of valve rod 68 by adjustable discs III which control operation of distributing valve 18.

The traversing mechanism including the bracket 40 and sleeve 42 is controlled by distributing valve 82 the pressure admitted to which being regulated by throttle valve 84. Reversals of movement of the transverse mechanism are controlled by movement of valve rod 43 by discs 45.

lhe oscillating movements of member 20 are controlled by distributing valve 86 which, as shown, may be supplied with pressure from the distributing valve 82. Unless traverse mechanism 4!] is operating and fluid is being returned to exhaust connection 90 of valve 82 the oscillating mechanism cannot function. Valve 86 admits fluid to opposite ends of cylinder 32. The valve 86 may be controlled by oscillation of member 3| oscillating a valve within valve casing 88.

I claim:

A lapping machine for cylindrical surfaces comprising in combination, a base, a spindle therein, an arbor on said spindle, means to rotate said spindle and arbor, a member reciprocated in a direction parallel to the axis of rotation of the spindle and arbor, a yoke member supported in said member for oscillation about an axis normal to the axis of the spindle, a work holder for the work piece being lapped, said holder having arms extending therefrom and engaging said yoke member, and a member oscillating about the axis of the spindle and arbor and having members alternately engaging one of said arms during oscillation thereof, whereby said work piece will be oscillated while traversed along said arbor.

2. A lapping machine for cylindrical surfaces comprising in combination, a base, a spindle therein, an arbor mounted for rotation co-axially with said spindle, means to rotate said spindle and arbor alternately in opposite directions, a member reciprocated in a direction parallel to the axis of rotation of the spindle, a yoke member supported within said member for oscillation about an axis normal to the axis of the spindle, a work holder for the work piece being lapped, said holder having arms extending therefrom and engaging said yoke member, and a member oscillating about the axis of the spindle andhaving members alternately resiliently engaging one of said arms of said work holder during oscillation thereof.

3. A lapping machine for cylindrical surfaces comprising in combination, a base, a spindle therein, an arbor on said spindle, means to rotate said spindle and arbor, a member reciprocated in a direction parallel to the axis of rotation of the spindle, a yoke member supported within said member for oscillation about an axis normal to the axis of the spindle, a Work holder for the work piece being lapped, said holder having arms extending therefrom and engaging said yoke member, and a member oscillating about the axis of the spindle and arbor engaging one of the arms of said work holder, whereby said work holder will be oscillated about its axis while being traver'sed on said arbor.

4. A lapping machine for cylindrical surfaces comprising in combination, a base, a spindle therein, an arbor on said spindle, means to rotate said spindle and arbor, a member reciprocated in a direction parallel to the axis of rotation of the spindle and arbor, a yoke member supported in said member for free adjustment about an axis normal to the axis of the spindle, a work holder for the work piece being lapped having arms extending therefrom engaging said yoke member, a member oscillating about the axis of the spindle and arbor, and resiliently supported elongated bars engaging one of said arms during oscillation thereof, whereby said work piece will be oscillated and traversed along said arbor while supported with'its surface being lapped in engagement with the surface of said arbor.

5. A lapping machine for cylindrical surfaces comprising in combination, a base, a spindle therein, an arbor on said spindle, means to rotate said spindle and arbor alternately in opposite directions, a member reciprocated in a direction parallel to the axis of rotation of the spindle, a yoke member supported within said member for oscillation about an axis normal to the axis of the spindle and arbor, a work holder for the work piece being lapped having arms extending therefrom engaging said yoke member, means to simultaneously rotate said spindle and traverse said reciprocated member, a member oscillating about the axis of the spindle and having members alternately resiliently engaging one of said arms of said work holder during oscillation thereof, and means to oscillate said last named member during traversing movements of work piece along said arbor.

ALDEN M. DRAKE. 

